Movably displaceable return gas pipe in a counter pressure filling machine

ABSTRACT

In a counter pressure filling machine including a liquid-gas chamber divided by a liquid level into a liquid space and a superposed pressurized gas space, a filling machine which does not use a filling tube communicates with the liquid space for filling a vessel. An axially displaceable gas return pipe extends through the filling member so that its outlet end communicates with the vessel to be filled and its opposite end is located within the gas space in the liquid-gas chamber. A cylinder of variable volume is connected to the end of the gas return pipe within the gas space. The cylinder includes at least one channel which can be opened and closed for admitting flow from the gas space into the gas return pipe. When a vessel is not being filled by the machine, the gas return pipe and the cylinder are sealed from the gas space and the interior of the gas space is maintained at atmospheric pressure. The liquid outlet part from the filling member is closed by a seal member mounted on the gas return pipe. During filling, when the pressure within the gas space and within the gas return pipe is equalized, the gas return pipe along with the seal member are axially displaced so that the liquid outlet part is opened.

[ Sept. 10, 1974 ABSTRACT outlet end communicates pipe and the cylinder nd the interior of the g member is closed by gas return pipe. During hin the gas space and gas return y displaced Agent, or Firm'l"oren, McGeady and by the machine, the gas return are sealed from the gas space a gas space is maintained at atmospheric pressure. The liquid outlet part from the fillin a seal member mounted on the Primary Examiner-Houston S. Bell, Jr. Assistant ExaminerFrederick R. Schmidt Attorney,

Stanger In a counter pressure fillin uid-gas chamber divided b space and a superposed pressurized machine which does not use a filli cates with the liquid space for fillin ally displaceable gas return filling member so that its Friedrich Rademacher, Kamen-Sudkamen, Germany Maschinenfabrik Phonix GmbH, Dortmund, Germany Jan. 15, 1973 Germany.............,,............. 2202292 141/39, 141/392 B65b 31/04 141/6, 39-43, ,90,102,l15,l47,181, 245, 392, 47, 285, 301, 302, 303, 307-310, 367, 368

References Cited m" a S an m d d We 8 .ur m m o m .HeMBM ECfi m wemWD w t5 pew M rm m 4 mmon J 0 I t nw 8 V & i g a u ,7 he

h wm m mwzmmm H uP W. l .10 I fiWD-S PIPE IN A COUNTER PRESSURE FILLING MACHINE [7 5] Inventor:

[73] Assignee: Holstein & Kappert [22] Filed:

[21] Appl. No.: 323,640

[30] Foreign Application, Priority Data Jan. 19, 1972 [51] Int.

[58] Field of United States Patent [191 Rademacher MOVABLY DISPLACEABLE RETURN GAS PATENIEU SEP! 0 I974 SHEET 2 0r 5 Y Ali\ nag L FIG, 2

PATENTED 3.834.428

sum u or 5 FIG.4

' saw-.428

PAIENIEU SEP 1 01914 SHEEISUF 5 FIGS MOVABLY DISPLACEABLE RETURN GAS PIPE IN A COUNTER PRESSURE FILLING MACHINE SUMMARY OF THE INVENTION The present invention is directed to a counter pressure filling machine and, more particularly, it concerns such a machine which utilizes a filling element without a filling tube and includes a gas return pipe axially displaceable relative'to the filling element.

The invention is based on known filling elements without filling tubes for counter pressure filling machines which use a liquid valve that opens automatically when the pressure between the filling tank and the bottle to be filled is equalized. The bottle or other vessel to be filled is secured under a filling element and, initially, after the gas valve is opened, the vessel is brought to a pressure equal to that of the tank in the filling machine. Next, the liquid valve which operates independently of the gas valve, is opened by spring force and the liquid flows into the vessel. As the vessel is filled, the gas contained with the vessel flows back into the gas chamber or space in the filling machine through the gas pipe in exchange with the liquid being filled. As soon as the vessel is filled, the liquid flows up through the gas pipe to a height equal to the liquid level in the filling machine tank. Subsequently, the gas valve is closed and the liquid remaining in the return gas pipe below the gas valve flows into the vessel.

In general, a rather high filling output can be achieved with such filling elements. One disadvantage, however, is that the cleaning of such filling elements, which consist of a relatively great number of parts, can only be carried out satisfactorily with considerable cost. Further, another disadvantage is that the liquid remaining in the return gas pipe after the filling operation must be removed and this results in a considerable disturbance to the contents of the vessel, particularly when the contents are carbonated beverages. Moreover, the liquid contained in the liquid outlets cannot be prevented from running, particularly in filling elements with liquid outlets designed as ring conduits.

Therefore, it is the object of the present invention to overcome the above mentioned disadvantages by providing a substantially simplified filling element for a counter pressure filling machine.

Another object of the present invention is to regulate the filling operation directly by means of the gas return pipe.

Moreover, another object of the invention is to discharge the liquid remaining in the return gas pipe without the requirement for any additional controlling operations.

In accordance with the present invention, an axially displaceable gas return pipe is combined with a filling element without a filling tube, such as mentioned above, and a cylinder of a variable volume is connected to the end of the return gas pipe within the gas space of the liquid-gas chamber of the filling machine. The cylinder acts as a differential member for affording the axial displacement of the return gas pipe relative to the vessel to be filled. Further, the cylinder is provided with channels, closable by valve means, which affords the flowof gas from the gas space into the cylinder and then into the return gas pipe. Further, the end of the return gas pipe which extends into the vessel is provided with a seal member which closes the liquid outlet part fromthe filling element when the return gas pipe is in its upwardly displaced position.

Another feature of the invention is the placement of a member having a variable volume at the end of the return gas pipe located within the gas space in the liquid-gas-chamber. The member or cylinder connected to the return gas pipe is arranged so that it can be sealed off from the pressure existing within the gas space. Further, the member is arranged so that the pressure existing in the gas 'spac'e exerts a displacing force against the member.

As compared to known filling elements, the filling element embodying the present invention has not only the great advantage of a simple design, but is has the further important advantage in permitting the discharge of the return gas 'pipe while the vessel being filled is still pressurized. This discharge operation is attained by the valve action incorporated into the filling element. In addition, outlet elements which in the past led to an over running of the filling liquid, are avoided by the present invention.

Another distinguishing feature of this invention is the use of a variablevolume cylinder as the member associated with the end of the gas return pipe within the gas space. The cylinder is associated with the upper wall of the liquid-gas chamber and its axial displacement toward the upper wall provides the variability in its volume. Further, channels are provided through the cylinder communicating with the gas space and a packing washer is provided on the return gas pipe for effecting the closure of the channel for preventing the pressure within the gas space from acting within the cylinder.

In a particularly advantageous embodiment of the invention, the cylinder within the gas space is guided on a stationary piston secured to and depending downwardly from the upper wall of the liquid-gas chamber. A compressible packing member is provided on the piston which provides the sealing action with the return gas pipe and, when the return gas pipe is displaced downwardly, the piston affords communication between the cylinder at the upper end of the pipe and the gas space. Moreover, another distinguishing feature of the present invention is the provision of a supporting element intermediate the ends of the return gas pipe which limits the lower position to which the return gas pipe can be displaced. The supporting, element can be movably secured on the return gas pipe for adjusting the lowermost position of its outlet.

As a result, the setting of the filling height in accordance with the conditions involved, can be selected inside the tank, independently of the closing action of the liquid outlet port.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 isa vertical-sectional view of a filling element, embodying the present invention, arranged in th closed position;

DETAILED DESCRIPTION OF THE INVENTION In the drawing a conventional liquid-gas chamber 1 of a filling machine, not shown, is provided with a filling element 2 shown in the closed condition in FIG. 1 and in the opened condition in FIG. 2. The filling element 2 consists of a' valve housing 3 attached to the lower surface of the chamber 1 so that it communicates with the body of liquid within the chamber. Extending vertically downwardly through the chamber 1 into and through the valve housing 3 of the filling element 2 is an axially displaceable return gas pipe 4. Within the valve housing, channels 5 and 6 are provided which lead to individual vacuum or relief valves. The valve housing 3 forms an outlet pipe connection 7 tapering inwardly immediately above its lower cylindrically shaped outlet part 8. Laterally enclosing the valve housing is a centering tulip 9 which can be moved in the axial direction relative to the valve housing by means of a lifting device, not shown. At the lower end of the centering tulip, a packing 10 is provided which seats against the upper end of a vessel 11 when the tilling element is in the open condition, note FIG. 2.

The end of the return gas pipe 4 extending through the outlet part 8 of the valve housing 3 is provided with a packing element 12 which provides a closure for the outlet part, note FIG. 1. The packing element is supported by a guide 13 mounted on the return gas pipe and centered within the lower portion of the outlet pipe connection 7 and its outlet part 8. Preferably, the guide 13 has a conical taper and a plurality, of liquid guide grooves 14 are arranged on its outer surface. The guide grooves 14 extend obliquely from the surface of the guide 13. The webs defining the grooves 14 are guided in the cylindrically shaped outlet part 8. Intermediate the ends of the return gas pipe 4, a supporting element 16 is positioned which can be movably located along the pipe by means of the distance discs 15. When the filling element is in the open condition the supporting element 16 rests on the upper end of the valve housing 3, note FIG. 2. Accordingly, the location of the supporting element 16 on the return gas pipe 4 determines the lowermost position of the return gas pipe outlet 32.

The liquid-gas chamber is divided into a lower liquid space and an upper gas space by means of the liquid level 17. Within the gas space, a cylinder 18 acting as a differential volume member is connected to the upper end of the return gas pipe 4. At its upper end, the

cylinder 18 supports a compressible packing 19 which is pressed against the surface of the upper wall 20 of the chamber when the filling element is in the closed condition, note FIG. 1. Channels 21 formed in the cylinder.

for closing off communication between the channels and the gas space. The movement of the packing on the pipe is provided by means of a control device, not shown. Encircling the upper end of the pipe 4 is a sleeve 24 having laterally extending flanges or angle plates 25 and the upper end of the sleeve supports the packing 22. Arms 23 of the control device effect the movement of the sleeve 24, at its lower end the sleeve is under the biasing action of a compression spring 26. Depending downwardly from the upper wall 20 of the chamber 1 is a guide pin 27 which extends into the cylinder 18 and the return gas pipe 4. The guide pin 27 provides both a centering and guiding action for the return gas pipe 4 in connection with its axial displacement within the cylindrically shaped part 8 of the outlet pipe connection 7. Gas passages 28 are formed on the surface of the guide pin 27.

ELEMENT As illustrated in FIG. 1, in the closed condition of the filling element, the packing element 12 seats against the outlet pipe connection 7 at the lower end of its cylindrically shaped part 8 so that no liquid can flow downwardly out of the filling element. Further, at the upper end of the return gas pipe, the cylinder 18 through. its packing 19 bears against the upper wall 20 of the chamber 1. The channels 21 communicating with the interior of the cylinder are closed by the packing 22 which is held in the upper position by the arms 23 of the control device which biases the sleeve 24 in the upward direction so that it is not possible for the gas to flow from the gas space into the cylinder. In this closed condition of the filling element, the interior of the cylinder is exposed to atmospheric pressure. On the outer surface of the cylinder, however, the pressurized gas within the chamber exercises a displacing force against the cylinder and maintains him its upper position. Only after pressure equalization has been attained, that is, when the pressure within the interior of the cylinder is equal to that in the gas space in the chamber, is it possible for the return gas pipe 4 to move along with the cylinder 18 into the lower position, as indicated in FIG. 2.-

An empty vessel 11, open at its top, is fed by a conveyor, not shown, to a preferably stationary tray 29 and it is centered on the tray. Subsequently, the centering tulip 9 is lowered so that its packing 10 contacts the upper end of the vessel. The downward movement of the centering tulip is effected by means of a fork, not shown, which engages in a recess 30 formed in the sides of the centering tulip. Initially, the return gas pipe 4, which pressurizes the vessel 11, remains in the upper position due to the differential pressures acting on the cylinder 18. When the control device, not shown, moves the sleeve downwardly by means of its arms 23 against the biasing action of the compression spring 26, the channels 21 are opened and the pressurized gas flows into the cylinder and then down through the bore 31 of the return gas pipe into the vessel 11. As soon as pressure equalization is established between the liquidgas chamber 1 and the vessel 11, the return gas pipe 4 moves axially downwardly under its own weight into its lowermost position limited by the supporting element 16. As the return gas pipe 4 moves downwardly, the packing element 12 is axially displaced from the lower end of the outlet pipe connection 7 so that the liquid from the chamber can flow into the vessel. In accordance with the embodiment illustrated in FIGS. 1 and 2, at first a low speed flow takes place through the relatively narrow ring slot formed between the guide 13 and the cylindrically shaped part 8 and also through the guide grooves 14 formed on the surface of the guide. However, when the return gas pipe reaches its lowermost position, the tapered guide 13' forms a correspondingly wider ring slot for a more rapid flow of the liquid into the vessel. As the filling operation proceeds, the pressurized gas in the vessel is displaced by the liquid and flows upwardly through the bore 31 of the return gas pipe 4 and through the channels 28 in the guide pin 27 into the open cylinder and then into the gas space in the chamber 1.

The filling of the vessel is completed as soon as the liquid level in the vessel reaches the outlet port 32 at the lower end of the return gas pipe 4 with the liquid outlet connection 7 in the open condition. Accordingly, the liquid rises upwardly through the bore 31 of the return gas pipe approximately to the liquid level 17 within the chamber. At the same time, the arms 23, controlled from outside the machine, move into the upper position, and with this movement the channels 21 in the cylinder 18 are closed by the packing 22. Next, the packing on the upper end of the cylinder moves into contact with the surface of the upper wall ized between the gas space and the vessel, the cylinder 33 and the return gas pipe 4 drop downwardly into their lower positions and the channels 40 located in the lower end of the piston 34 are open between the gas space and the cylinder. Accordingly, the vessel can be pressurized by the flow of gas from the gas space through the channels 40 and the bore 31 into the vessel. Similarly, the return flow of the pressurized gas passes upwardly through the bore and the channels 40 into the gas space. During the upward movement of the cylinder 33 toward the upper wall 20, its volume is reduced automatically by the introduction of the piston into the cylinder and the amount'of liquid contained in the gas return pipe and the bore 31 is discharged into the vessel 11.

Another embodiment of the cylinder arrangement at the upper end of the return gas pipe is shown in FIG.

' 4. In this embodiment the cylinder is designed as a bel- 20 of the chamber 1 and the pressure communication between the vessel and the gas space in the chamber is broken. The volume of the cylinder 18 is reduced further by the movement of the return gas pipe 4 to the upper position by the pressure of the packing. The difference in volume formed when the packing bears against the surface of the upper wall 20 and the reduced volume in the final upper position of the return gas pipe 4 corresponds approximately to the amount of liquid contained in the bore 31 and the liquid is automatically added intothe vessel 11 and the vessel is still in its pressurized condition. As a result, when the vessel is subsequently relieved, there is no additional spraying off of the liquid which had risen in the gas return pipe and, accordingly, there is no disturbance to the contents of the vessel. The relieved vessel 11 is separated from the packing 10 by moving the centering tulip 9 upwardly and in the further course of the operation of the machine the vessel is removed from the stationary tray 29 and is closed in a following operation.

In FIG. 3 another embodiment of the variable volume at the upper end of the return gas pipe is shown consisting of a cylinder 33 connected to the upper end of the return gas pipe and guided on a piston 34 secured to and depending downwardly from the upper wall of the liquid-gas chamber 1. A packing 35 secured by a packing washer 36 is located around the upper end of the piston and provides a seal against the communication of the pressurized gas in the gas space with the cylinder when the end face 37 of the cylinder bears tightly against the packing 35. At the lower end of the cylinder 33, channels 38 are provided which communicate with the gas space and these channels can be closed by means of the packing 39 encircling the upper end of the gas return pipe. When the end face 37 of the cylinder 33 bears against the packing 35, the pressure within the gas space affords an upwardly displacing force on the cylinder and keeps it in the upper position, due to the lower atmospheric pressure within the cylinder. When the channels 38 are opened and the pressure is equallows 41 which is supported by a spring-loaded sleeve 42. Further, a cylinder in the form of a corrugated tube spring is also possible.

In-the embodiment represented in FIG. 5, the guidance of the lower end of the return gas pipe is provided by the supporting element 16. As mentioned above, the position of the supporting element on the return gas pipe can be varied by means of the distance discs 15. The supporting element is guided during the axial displacement of the return gas pipe within a recess 43 in the upper end of the valve housing 3. Adjacent its lower end, the return gas pipe 4 has a cylindrical sleeve 44 which fits within a filter packing 45 supported in the valve housing 3. The packing element 12 located at the lower end of the sleeve 44 serves as a deflecting member for the liquid flowing out of the valve housing. In this'arrangement the surface of the packing element is provided with guide grooves in the form of teeth which can be straight, curved or inclined.

For the accelerated downward displacement of the return gas pipe 4 when pressure equalization has been reached for opening the liquid valve, mechanically, electrically or pneumatically operated release supports can be provided. When such release supports are used, they are arranged preferably above the liquid-gas chamber. It is also possible to provide detachable means for the return gas pipe on the valve housing 3.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise including a stationary valve housing attached to said chamber and said valve housing forming a liquid outlet part from the liquid space in said chamber, a centering tulip positioned on said valve housing, a packing member mounted on said centering tulip and arranged to be displaced with said centering tulip into contact with the opening in a vessel to be filled, and an upwardly disposed axially displaceable return gas pipe extending through said valve housing and into said liquid-gas chamber and having its upper end located in the gas space and being displaceable between an upper position where flow through said liquid outlet part is closed and a lower position where flow through said liquid outlet part is open, wherein the improvement comprises that a cylinder is connected to said return gas pipe within the gas space and forms a continuation of the flow passage through said return gas pipe, said cylinder is axially displaceable with said gas return pipe so that its volume is variable between the upper position and the lower position of said return gas pipe, said cylinder having channels therein communicating with said gas space, means associated with said cylinder for closing said channels, said cylinder arranged to provide an opening to said gas space at a position spaced from said channels therein when said return gas pipe is in the lower position and to have the opening closed when said return gas pipe is in the upper position, said cylinder being shaped so that the pressurized gas in the gas space exerts an upwardly displacing force on said cylinder when said return gas pipe is in the upper position, and a seal member mounted on said return gas pipe and arranged to form a closure for said liquid outlet part of said valve housing when said return gas is in the upper position.

2. In a filling machine, as set forth in claim 1, wherein said cylinder is mounted onthe upper end of said return gas pipe located within said gas space, said wall means comprising an upper wall defining the top of said chamber and arranged to be spaced upwardly from the liquid level therein, said cylinder being displaceable toward said upper wall as said gas return pipe is moved into the upper position and as it is displaced toward said upper wall its volume is reduced, and said means for closing said channels in said cylinder comprises a packing member mounted on said return gas pipe for displacement in the axial direction thereof.

3. In a filling machine, as set forth in claim 2, wherein a stationary piston is secured to and depends downwardly from said upper wall of said chamber, a compressible packing mounted on said piston, said cylinder being axially displaceable on said piston and when said return gas pipe is in its upper position said cylinder contacts said packing, said piston having at least one channel formed therein arranged to communicate between said gas space and said gas return pipe when said gas return pipe is in its lower position and said cylinder is displaced downwardly with it so that said channel is open and when said return gas pipe is moved into its upper position and said cylinder is displaced upwardly on said piston said channel and said piston is closed off from communication with said gas space.

4. In a filling member, as set forth in claim 2, wherein a guide pin is secured to and depends downwardly from said upper wall into said cylinder in alignment with said return gas pipe, said cylinder having a compressible packing located at its upper end and said compressible packing is arranged to contact said upper wall when said cylinder is displaced upwardly with said return gas pipe into the upper position of said return gas pipe.

5. In a filling machine, as set forth in claim 2, wherein said cylinder comprises a bellows member.

6. In a filling machine, as set forth in claim 2, wherein said cylinder comprises a spring biased corrugated tube.

7. In a filling machine, as set forth in claim 2, wherein a guide is located on and adjacent the end of said gas return pipe extending through said valve housing, said guide supporting said seal member and centered within said liquid outlet part of said valve housing, said guide having a conically tapering outer surface with a plurality of liquid guide grooves formed in its outer surface with the grooves extending obliquely to the surface of said guide.

8. In a counter pressure filling machine including wall means forming a liquid-gas chamber arranged to contain a liquid level therein for separating the chamber into a lower liquid space and a superposed gas space with said gas space arranged to contain a pressurized gas, a filling member arranged in communication with the liquid space in said chamber, said filling member including a stationary valve housing attached to said chamber and said valve housing forming a liquid outlet part from the liquid space in said chamber, a centering tulip positioned on said valve housing, a packing member mountedon said centering tulip and arranged to be displaced with said centering tulip into contact with the opening in a vessel to be filled, and an upwardly disposed axially displaceable return gas pipe extending through said valve housing and into said liquid-gas chamber and having its upper end located in the gas space and being displaceable between an upper position where flow through said liquid outlet part is closed and a lower position where flow through said liquid outlet part is open, wherein the improvement comprises that said return gas pipe extends downwardly through said liquid outlet part of said valve housing and has an outlet at its lower end, a support element mounted on said return gas pipe intermediate the ends thereof, said valve housing forming a seat for said support element when said gas return pipe is in its lower position, means for selectively securing the position of said support element along the axial direction of said return gas pipe so that when said support element'rests on the seat in said valve housing said support elements limits the downward displacement of said return gas pipe and establishes the position of the outlet from said return gas pipe relative to the lower end of said valve housing. 

1. In a counter pressure filling machine including wall means forming a liquid-gas chamber arranged to contain a liquid level therein for separating the chamber into a lower liquid space and a superposed gas space with said gas space arranged to contain a pressurized gas, a filling member arranged in communication with the liquid space in said chamber, said filling member including a stationary valve housing attached to said chamber and said valve housing forming a liquid outlet part from the liquid space in said chamber, a centering tulip positioned on said valve housing, a packing member mounted on said centering tulip and arranged to be displaced with said centering tulip into contact with the opening in a vessel to be filled, and an upwardly disposed axially displaceable return gas pipe extending through said valve housing and into said liquid-gas chamber and having its upper end located in the gas space and being displaceable between an upper position where flow through said liquid outlet part is closed and a lower position where flow through said liquid outlet part is open, wherein the improvement comprises that a cylinder is connected to said return gas pipe within the gas space and forms a continuation of the flow passage through said return gas pipe, said cylinder is axially displaceable with said gas return pipe so that its volume is variable between the upper position and the lower position of said return gas pipe, said cylinder having channels therein communicating with said gas space, means associated with said cylinder for closing said channels, said cylinder arranged to provide an opening to said gas space at a position spaced from said channels therein when said return gas pipe is in the lower position and to have the opening closed when said return gas pipe is in the upper position, said cylinder being shaped so that the pressurized gas in the gas space exerts an upwardly displacing force on said cylinder when said return gas pipe is in the upper position, and a seal member mounted on said return gas pipe and arranged to form a closure for said liquid outlet part of said valve housing when said return gas is in the upper position.
 2. In a filling machine, as set forth in claim 1, wherein said cylinder is mounted on the upper end of said return gas pipe located within said gas space, said wall means comprising an upper wall deFining the top of said chamber and arranged to be spaced upwardly from the liquid level therein, said cylinder being displaceable toward said upper wall as said gas return pipe is moved into the upper position and as it is displaced toward said upper wall its volume is reduced, and said means for closing said channels in said cylinder comprises a packing member mounted on said return gas pipe for displacement in the axial direction thereof.
 3. In a filling machine, as set forth in claim 2, wherein a stationary piston is secured to and depends downwardly from said upper wall of said chamber, a compressible packing mounted on said piston, said cylinder being axially displaceable on said piston and when said return gas pipe is in its upper position said cylinder contacts said packing, said piston having at least one channel formed therein arranged to communicate between said gas space and said gas return pipe when said gas return pipe is in its lower position and said cylinder is displaced downwardly with it so that said channel is open and when said return gas pipe is moved into its upper position and said cylinder is displaced upwardly on said piston said channel and said piston is closed off from communication with said gas space.
 4. In a filling member, as set forth in claim 2, wherein a guide pin is secured to and depends downwardly from said upper wall into said cylinder in alignment with said return gas pipe, said cylinder having a compressible packing located at its upper end and said compressible packing is arranged to contact said upper wall when said cylinder is displaced upwardly with said return gas pipe into the upper position of said return gas pipe.
 5. In a filling machine, as set forth in claim 2, wherein said cylinder comprises a bellows member.
 6. In a filling machine, as set forth in claim 2, wherein said cylinder comprises a spring biased corrugated tube.
 7. In a filling machine, as set forth in claim 2, wherein a guide is located on and adjacent the end of said gas return pipe extending through said valve housing, said guide supporting said seal member and centered within said liquid outlet part of said valve housing, said guide having a conically tapering outer surface with a plurality of liquid guide grooves formed in its outer surface with the grooves extending obliquely to the surface of said guide.
 8. In a counter pressure filling machine including wall means forming a liquid-gas chamber arranged to contain a liquid level therein for separating the chamber into a lower liquid space and a superposed gas space with said gas space arranged to contain a pressurized gas, a filling member arranged in communication with the liquid space in said chamber, said filling member including a stationary valve housing attached to said chamber and said valve housing forming a liquid outlet part from the liquid space in said chamber, a centering tulip positioned on said valve housing, a packing member mounted on said centering tulip and arranged to be displaced with said centering tulip into contact with the opening in a vessel to be filled, and an upwardly disposed axially displaceable return gas pipe extending through said valve housing and into said liquid-gas chamber and having its upper end located in the gas space and being displaceable between an upper position where flow through said liquid outlet part is closed and a lower position where flow through said liquid outlet part is open, wherein the improvement comprises that said return gas pipe extends downwardly through said liquid outlet part of said valve housing and has an outlet at its lower end, a support element mounted on said return gas pipe intermediate the ends thereof, said valve housing forming a seat for said support element when said gas return pipe is in its lower position, means for selectively securing the position of said support element along the axial direction of said return gas pipe so that when said support element rests on the seat in said valve housing said support elemEnts limits the downward displacement of said return gas pipe and establishes the position of the outlet from said return gas pipe relative to the lower end of said valve housing. 